The α2,8-sialyltransferase 6 (St8sia6) localizes in the ER and enhances the anchorage-independent cell growth in cancer

Identification of a buried β-strand as a novel disease-related motif in the human polysialyltransferases

“…After washing, the cells were permeabilized with 0.1% TritonX-100 in PBS at room temperature for 15 min. The permeabilized cells were blocked with PBS containing 2% BSA for 1 h and then incubated with the following primary antibodies diluted in blocking buffer for 1 h at room temperature: anti-V5 tag antibody (1:200) to detect the expression and localization of ST8SIA6, ST8SIA6 swapping mutants, ST8SIA2 and ST8SIA4, and the anti-TGN46 antibody (1:200) to detect trans -Golgi apparatus ( 19 ). After washing with PBS, the cells were incubated for 30 min with the following secondary antibodies diluted in blocking buffer: AlexaFluoro555-labeled anti-chicken IgY (1:1000) to visualize protein localization and Alexa Fluoro488-labeled anti-rabbit IgG (1:500) to visualize the localization marker.…”

“…ST8SIA2 (STX, SIAT8B) ( 16 , 17 ) and ST8SIA4 (PST-1, SIAT8E) ( 18 ) are polysialyltransferases (polySTs) characterized by their ability to synthesize polySia structures. STs are type II transmembrane proteins, and most of them are localized in the Golgi apparatus except ST8SIA6 ( 19 ). These enzymes are modified for correct folding by post-translational modifications such as glycosylation, S-S formation, and oligomerization.…”

Comprehensive Analysis of Oligo/Polysialylglycoconjugates in Cancer Cell Lines

“…Oligo/polySia structures are biosynthesized by ST8 α- N -acetyl-neuraminide α2,8-sialyltransferase (ST8SIA). Humans have six ST8SIA enzymes (ST8SIA1, 2, 3, 4, 5, and 6), and evidence indicates that these enzymes and oligo/polySia structures that are produced are related to tumor malignancy [ 7 , 8 , 9 , 10 ]. For example, ST8SIA1 and diSia ganglioside GD3 have been well studied in cancer [ 11 , 12 ].…”